How to consume a web service from VB6?

Question

I need to consume an external web service from my VB6 program. I want to be able to deploy my program without the SOAP toolkit, if possible, but that's not a requirement. I do not have the web service source and I didn't create it. It is a vendor-provided service.

So outside of the SOAP toolkit, what is the best way to consume a web service from VB6?

Answer 1

I use this function to get data from a web service.

Private Function HttpGetRequest(url As String) As DOMDocument
    Dim req As XMLHTTP60
    Set req = New XMLHTTP60
    req.Open "GET", url, False
    req.send ""

    Dim resp As DOMDocument
    If req.responseText <> vbNullString Then
        Set resp = New DOMDocument60
        resp.loadXML req.responseText
    Else
        Set resp = req.responseXML
    End If
    Set HttpGetRequest = resp
End Function

Answer 2

.NET has a good support for Web Services since day one, so you can develop your Web Service client logic in .NET as a .dll library/assembly and use it in VB6 app via COM Interop.

Answer 3

Assuming that you're running on Windows XP Professional or above, one interesting method is to use the SOAP moniker. Here's an example, lifted from some MSDN page. I don't know if this particular service works, but you get the idea...

   set SoapObj = GetObject
       ("soap:wsdl=http://www.xmethods.net/sd/TemperatureService.wsdl")
   WScript.Echo "Fairbanks Temperature = " & SoapObj.getTemp("99707")

This mechanism also works from VBScript. Which is nice.

Answer 4

Pocketsoap works very well. To generate your objects use the WSDL generator. Using this you don't have to parse anything yourself, plus everything is nice and strongly typed.